Methods for detecting misfolded proteins in biological samples

ABSTRACT

Compositions and methods for the isolation and manipulation of misfolded, or partially misfolded, proteins present in blood and other biological materials are provided. In one aspect of the invention, the compositions, hereinafter termed “proteons” are comprised of misfolded proteins. Also provided are compositions and methods for the isolation and manipulation of proteon nucleation centers (PNCs) upon which the proteons of the present in blood and other biological materials form. In another aspect of the invention, the PNCs are comprised of metallic nanoclusters.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. application Ser. No.10/674,750 filed on Sep. 30, 2003, which claims the benefit of U.S.Provisional Application Ser. No. 60/415,108 filed on Sep. 30, 2002,which is hereby incorporated in its entirety by reference herein.

FIELD OF THE INVENTION

The present invention relates generally to compositions and methods forthe isolation and manipulation of misfolded proteins and theirnucleation centers.

BACKGROUND OF THE INVENTION

There are many disorders that are thought to arise form the same generalmechanism based upon misfolding and aggregation of underlying proteins,including prion-related disorders, neurodegenerative diseases, andseveral systematic disorders. See, for example, Schluter et al. (1986)PNAS 83:6137-6141; Kannan et al. (1988) J. Biol Chem. 263:3766-13773;Carrell and Lomas (1997) Lancet 350:134-138; Carrell and Gooptu (1998)Curr. Op. Struc. Biol. 8:799-809; Soto (2001) FEBS Letters 498:204-207;Jaikaran and Clark (2001) Biochimica et Biophysica Acta 1537:179-203;Ursini et al. (2002) Trends Mol. Med. 8:370-374; and Davis et al. (2002)Lancet 359:2242-2247.

One of the suggested mechanisms of protein aggregation is seededpolymerization, in which initial seeds nucleate the deposition ofmonomers. For example, aggregates of denatured hemoglobin called Heinzbodies where found in ages erythrocytes. See Schluter et al. (Supra).Further, Kannan et al. (Supra) described a protein aggregation fromsickle erythrocytes that is mostly composed of globin. Particlesresembling those described by Enderlein (1925) Bakterien-Cyclogenie(Verlag d Gruyter & Co, Berlin), were isolated form the blood of cancerpatients and determined to be composed of mainly denatured hemoglobin(Gerner (1997) Blut. Curr. Onokol. 7:6P12).

Aggregated proteins associated with disorders are found in otherbiological materials, as well. For example, proteinaceous particlesisolated from brain were identified as causing scrapie (Prusiner (1982)Science 216:136-144). Since then, these particles and their structurehave represented important areas of study (Prusiner (1991) Science252:1515-1522; Wille et al. (2002) Biophysical J. 82:825; Wille et al.(2002) PNAS 99:3563-3568; Greschwind et al. (2002) Neurology58:A135-A135; Dyson et al. (2002) Biophysical J. 82:824), and methodsfor the sensitive detection fluid of patients with schizophrenia(Wetterberg et al. (2002) Neurosci Lett. 329:91-5). Accordingly, newcompositions and methods for the formation, isolation, and detection ofmisfolded, aggregated proteins are required.

BRIEF SUMMARY OF THE INVENTION

Compositions and methods for the isolation and manipulation ofmisfolded, or partially misfolded, proteins present in blood and otherbiological materials are provided. In one aspect of the invention, thecompositions, hereinafter termed “proteons,” are comprised of misfoldedproteins. Also provided are compositions and methods for the isolationand manipulation of proteon nucleation centers (PNCs), upon which theproteons of the present invention form. The PNCs are comprised ofmetallic nanoclusters.

Proteons can be visualized by microscopy of biological materials, forexample fluids such as blood samples of mammals and homogenates ofvegetable matter. As proteons are comprised of misfolded proteins,detection of proteons and identification of proteins can be used todiagnose and measure progression of disease states. For example,proteons isolated and purified from blood and blood plasma lackdetectable nucleic acids, but contain two major poly peptide populationswith high homology to the alpha chain of hemoglobin. Accordingly,methods for the amplification and detection of misfolded protein inbiological sample are provided. Additionally, methods for the clearanceof misfolded protein from a sample biological material are provided. Themethod can be manipulated by subjecting the sample to heat or pressure,or by carrying out various numbers for seeding steps. Methods foramplification include heat and pressure treatment of a sample. Likewise,subjecting a biological sample to or treating it with metal clustersincreases the concentration of proteons.

While the present invention is not bound to any particular mode ofaction, it is believed that proteons are formed by a mechanism involvingthe reversible polymerization and aggregation of proteins, particularlymisfolded proteins, on a nucleation center. For convenience, thenucleation centers are referred to as “proteon nucleation centers” or“PNCs.”

The PNCs of the invention are unexpectedly pro-apoptotic when added tocultured animal cells. Accordingly, pro-apoptotic compositions andmethods for their production are also provided herein.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 shows various electron micrographs of proteons in thin sections.Transmission electron microscopy (TEM) was used to prepare electronmicroscopy of type proteons. See FIG. 1A and FIG. 1B. Also shown are TEMof type 2 proteons. See FIG. 1A and FIG. 1B. Also shown are TEM of type2 proteons. See FIG. 1C and FIG. 1D. TEM of negatively stained type 2proteons are shown in FIG. 1E and FIG. 1F. A electron micrograph of atype 2 proteon prepared using scanning electron microscopy (SEM) isshown in FIG. 1G. Scale bars (in microns): FIG. 1A: 5; FIG. 1B-1F; 0.5;FIG. 1G: 1.

FIG. 1A is an electron micrograph prepared using transmission electronmicroscopy (TEM) of a type 1 proteon.

FIG. 1B is a TEM electron micrograph of another type 1 proteon.

FIG. 1C is a TEM electron micrograph of a type 2 proteon.

FIG. 1D is a TEM electron micrograph of another type 2 proteon.

FIG. 1E is a TEM electron micrograph of a negatively stained type 2proteon.

FIG. 1F is a TEM electron micrograph of another negatively stained type2 proteon.

FIG. 1G is an electron micrograph prepared using scanning electronmicroscopy (SEM) of a type 2 proteon.

FIG. 2A is a graph illustrating proteon proliferation in purified waterand in blood plasma showing the number of proteons visible as a functionof time.

FIG. 2B is a graph of proteon proliferation in two different growthmediums showing the number of proteons visible as a function of time.

FIG. 2C is a graph of proteon proliferation in the presence and absenceof urea showing the number of proteons visible as a function of ureaconcentration.

FIG. 2D is a graph illustrating cyclic amplification of proteons inplasma showing the number of proteons visible as a function of thenumber of amplification cycles.

FIG. 3A is a TEM electron micrograph of clusters of crystalline,metallic copper nanoparticles.

FIG. 3B is a TEM electron micrograph of an amorphous matrix for thecopper nanoparticles shown in FIG. 3A.

FIG. 3C is a SAD pattern identifying the copper nanoparticles in FIG.3A.

FIG. 3D is a DF image of copper nanoparticles prepared using a portionof FCC ring of FIG. 3C.

FIG. 4A is a three-dimensional bar graph illustrating the viability ofthree different cultured cells after exposure to proteon nucleationcenters (PNCs) obtained from shark blood at four differentconcentrations of PNC/ml.

FIG. 4B1 shows a dark filed photomicrograph of brain glioma cells beforeexposure to PNCs.

FIG. 4B2 shows a dark field photomicrograph of brain glioma cells afterexposure to PNCs.

FIG. 4B3 is a dark field photomicrograph of brain glioma cells afterexposure to a staurosporine.

FIG. 4B4 is a fluorescenen photomicrograph of brain glioma cells exposedto PNCs and stained with propidium iodide.

FIG. 4C is a graph illustrating the viability of brain glioma cellsobtained from various animals after exposure to PNCs at differentconcentrations.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 shows proliferation of proteons. Proteons in purified water andblood plasma incubated at 37° C. in an atmosphere of ambient air,showing the number of proteons visible in the dark-field microscope as afunction of time. See FIG. 2A. Proteons and plasma were incubated intissue culture media, ▪, ●—proteons and plasma in culture growth medium,respectively; ▴, ▾—D5648 and D6429 growth medium, respectively. Theinsert shows a linear fit of the experimental data to the logisticequation Ln(L/N−1)=k(T_(1/2)−t), where L=maximal number of proteons,N=number of proteons at time t, and T_(1/2)=time when N=L/2 (Jarman,1970). See FIG. 2B. Assembly and disassembly of proteons in the presentsof urea is shown in FIG. 2C. After the proteons were assembled in thepresence of urea, the urea was then removed from the suspension ofproteons by dialysis. Cyclic amplification of proteons in plasma isshown in FIG. 2D. The first sample was incubated for 15 minutes at 65°C. and normal pressure. Treated samples of 5 μL were serially introducedinto untreated sample and subjected to a heat cycle, up to 6 cycles.

FIG. 3 shows characterization of Cu nanoparticles using TEM, with a-Feparticles shown for comparison. A BF image showing clusters ofcrystalline, metallic Cu nanoparticles is shown in FIG. 3A. A BF imageof the amorphous matrix is shown in FIG. 3B. A SAD pattern identifyingthe nanoparticles in FIG. 3A as an FCC phase with a lattice parameter ofapproximately 360 pm and a random crystallographic orientation is shownin FIG. 3C. Centered DF image prepared using a portion of the {111} FCCring is shown in FIG. 3D. The nanoparticles appear bright, on a darkbackground, indicating that the {111} FCC diffraction maxima originatedfrom the nanoparticles and not the matrix (since the Cu particles arerandomly oriented, many of the particles are out of contrast). The insetshows clumped and individual a-Fe particles (DF from a portion of the{110} BCC ring). Scale bars shown in FIGS. A, B, and D represent 50 nm.Scale bars in the insert represent 20 nm.

FIG. 4 shows the effect of PNC on cell viability. FIG. 4A shows theviability of cultured cells after 20 hours of exposure to PNC obtainedfrom the shark blood at different concentrations of PNC/ml.: (1)−1.7×10¹¹; (2) −9.1×10¹⁰; (3) −9.9×10⁹; (4) −0. (F98, RG2—rat and mousebrain glioma cells respectively, CTX—rat transfected astrocytes). FIG.4B shows dark-field photomicrographs of the mouse rat glioma cells.FIGS. 4B1 and 4B2 show cells before after exposure to 7.7×10¹¹ PNC/ml,respectively. FIG. 4B3 shows cells after exposure to 1.0 μMstaurosporine. 4-Fluorescence photomicrograph of RG2 glioma cell exposedto 7.7×10¹¹ PNC/ml for 20 h and stained with Annexin V and propidiumiodide (400X). FIG. 4C shows viability of RG2 glioma cultured cellsafter 20 hours of exposure to PNC obtained from the blue shark(Prionance) (▪), hound dog, (●), human (▴), and New Zealand white rabbit(Harland Sprague Dawley) (▾) blood at different concentrations. R=0.95,p<0.0001.

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the invention are shown. Indeed, the invention may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements.

Compositions and methods for identifying and characterizing diseasestates are provided. The compositions comprise misfolded proteinsaggregated on a nucleation center. The aggregated proteins are referredto herein as proteons. The nucleation centers are referred to as proteonnucleation centers (PNCs).

DEFINITIONS

By “proteons” are intended protein bodies, generally on the order of afew tens of nanometers up to several microns across, comprised ofmisfolded or partially misfolded proteins surrounding a PNC. In oneaspect of the invention, proteons can be isolated from blood, includinghuman, bovine, horse, pig, cat, dog, fish, rabbit, and rat blood. Inanother aspect of the invention proteons can be isolated from plasma,including human, bovine, horse, pig, cat, dog, fish, rabbit and ratplasma.

By “PNC” is intended the metallic nucleation centers isolated asdescribed herein. In one aspect of the invention, PNCs can be isolatedfrom blood, including human, bovine, horse, pig, cat, dog, fish, rabbit,and rat blood. In another aspect of the invention, PNCs can be isolatedfrom plasma, including human, bovine, horse, pig, cat, dog, fish, rabbitand rat plasma.

By “plasma” is intended the supernatant produced by the centrifugationof blood or other suspension of biological material.

By “seeding” is intended adding an amount of either a PNC or proteon toa biological sample.

The proteons of the invention can be identified and quantified inbiological samples. Such samples include serum, blood, other bodilyfluids, tissue including brain, other organ tissue and the like. Toidentify the proteons in tissue, the tissue is homogenized in a fluid orliquid.

Proteons can be isolated from biological samples of any mammal includingbut not limited to human, primate, bovine, cattle, horse, sheep, pig,cat, dog, rabbit, rat, deer, ox, mouse, and the like. They can also bedetected in samples from fish, chicken, turkey, duck, and the like.

As indicated, proteons are comprised of misfolded proteins. In oneaspect, the proteon compositions of the invention show an apple-greenbirefringence when stained with congo-red. This staining pattern isanalogous to that obtained with prions and other amyloid proteins, allof which are included in the class of congophilic proteins. See Kelly(1996) Curr. Opin. Struct. Biol. 6:11-17. These proteins are associatedwith various disorders or disease states. Thus, the identification ofproteons comprised of such proteins is indicative of a disorder ordisease state. Likewise, the number of proteons in a sample comprised ofsuch proteins is predicative of the progression of the disease. That is,the number of proteons in a sample correlates with progression of adisease state. Therefore, quantification of proteons in a sample isuseful for determining or diagnosing the stage of disease or disorderand can help in planning treatments or therapies for the disease.Examples of disorders involving misfolded proteins and the relevantproteins that can be utilized in the methods of the present inventionare set forth in Table 1, below. The disorders associated withcongophilic proteins are set forth in Table 2, below.

It is recognized that for proper diagnosis, proteons must not only beidentified, but also the misfolded protein in the proteons must not onlybe identified, but also the misfolded protein in the proteon must beidentified. Methods for protein purification and identification includeantibody binding amino acid sequencing, and the like.

TABLE 1 Conformational diseases. See Carrel and Lomas (1997) Lancet 350:134-138; Carrell and Gooptu (1998) (1998) Curr. Op. Struc. Biol. 8:799-809; Soto (2001) FEBS letters 498: 204-207; Jaikaran and Clark(2001); Ursini et al. (2002) Trends Mol. Med. 8: 370-374; Kannan et al.(1988) J. Biol. Chem. 263: 13766-13773; Schluter and Drenckhahn (1986)PNAS 83: 6137-6141; Gerner et al. (2002); Davis et al. (2002) Lancet359: 2242-2247; Fernandez et al. (2001) Atherosclerosis 158, 103, 111(atherosclerosis); Papalexis et al. (2001) Mol. Biochem. Parasitology115: 77-86; Esievo et al. (1984) Veterinary Parasitology 15: 181-185;Igoe et al. (2002) Clin. Microb. Newsletter 24: 69-70; Kreidl et al.(2002) J. Am. Coll. Surgeons 194: 387; Beckers (2001) Netherlands J..Med 58: 207-207 (autoimmune diseases); Ismeno et al. (1999) Int'l J.Cardiology 69: 179-183; Klibansky et al. (1966) Toxicon 3: 213-216;Siebert et al. (2003) Toxicon 41: 831-839; Szabo et al. (2002)Thrombosis Research 107: 357-363; Kaioumova et al. (2001) Chemosphere43: 801-805. Protein Disease Hemoglobin Sickle cell anemia andaggregates Heinz bodies in ages erythrocytes Unstable hemoglobininclusion body hemolysis Drug induced inclusion body hemolysisAggregates regulate apoptosis in cancer patients Atherosclerosis MalariaInfections Auto-immune disorders Toxic reactions Internal bleedingsPrion Protein Creutzfeld-Jacob disease (CJD) New variant CJD Bovinespongiform encephalopathy (BSE) Gerstmann-Straussler-Schheinker diseaseFatal familial insomnia Kuru β-amyloid Alzheimer's disease Down'sSyndrome Familial Alzheimer's α-Synuclein Parkinson's disease, Lewybodies Tau protein Frontotemporal dementia, Pick bodies Serpinsα₁-antitrypsin deficiency cirrhosis emphysema Antithrombin deficiencythrombosis C₁-inhibitor deficiency angioedema NeuroserpinNeurodegenerative disease, Collins bodies Glutamate repeats Inheritedneurodegenerative disorders Huntington's disease Amylin Diabetes type IISOD Amyotrophic lateral sclerosis ApoB Atherosclerosis CFTR proteinCystic fibrosis Immunoglobulin Systemic amyloid light chain amyloidosisAmyloid light Nodular amyloidosis chain Serum amyloid A Reactivesystemic amyloid A amyloidoses Chronic inflammatory diseaseTransthyretin Senile systemic amyloidosis Familial amyloid neuropathyFamilial cardiac amyloid β₂-microglobulin Hemodialysis amyloidosisProstatic amyloid Apoliproprotein AI Familial amyloid polyneuropathyFamilial visceral amyloid Cystatin C Hereditary (Icelandic) cerebralangiopathy Lysozyme Familial visceral amyloidosis

TABLE 2 Congophilic disorders. See Kelly (1996) Curr. Opin. Struct.Biol. 6: 11-17. Disorder Acronym Disorder Protein Involved CJDSpongiform Prion protein fragments encepalopathies APP Alzheimer Betaprotein fragment 1- 40/43 HRA Hemodialysis-Related Beta-2 microglobin*Amyloidosis PSA Primary Systematic Immunoglobulin light Amyloidosischain and fragments SAA 1 Secondary Systematic Serum amyloid A 78Amyloidosis residue fragment FAP I** Familial Amyloid Transthyretinfragments, Polyneuropathy I 50+ alleles FAP III Familial AmyloidApolipoprotein A-1 Polyneuropathy III fragments CAA Cerebral AmyloidCystatin A minus 10 Angiopathy residues FHSA Finnish Hereditary Gelsolin71 residue Systemic Amyloidosis IAPP Type II Diabetes Islet amyloidpolypeptide fragment ILA Injection-Localized Insulin Amyloidosis CALMedullary Thyroid Calcitonin fragments Carcinoma ANF Atrial AmyloidosisAtrial natriuretic factor NNSA Non-Neuropathic Lysozyme and fragmentsSystemic Amylodosis HRA Hereditary Renal Fibrinogen fragmentsAmyloidosis *Homologous to immunoglobin, thus a predicted paralogousdisease. **Also called senile systemic amyloidosis, prealbumin issynonymous with transthyretin. See mad-cow.org/congo.html. (the prefix“www” is required).

Immunohistochemical assays have been developed for the proteins listedin Tables 1 and 2. See, e.g., Hardt et al. (2000) J. Comp. Path.122:43-53 (antibodies for the detection of the prion protein, PrP).However, many of these proteins are only abundant in the late stages ofthe disease and may be undetectable utilizing standard assay techniques.Thus, in one embodiment, the methods of the present invention may becombined with an immunochemical assay for the protein or proteinsselected from Tables 1 and 2. These proteins, or their functionalderivatives, may be detectably labeled with any appropriate marker suchas a radioisotope, an enzyme, a fluorescent label, a paramagnetic label,or a free radical linked to an antibody capable of binding theseproteins.

Methods of making and detecting such detectably labeled antibodies ortheir functional derivatives are well known to those of ordinary skillin the art, and are described in more detail below. See, for example,Klein (1982) Immunology: The Science of Self-Nonself Discrimination(John Wiley & Sons, New York 1982); Kennett et al. (1980) MonoclonalAntibodies and Hybridomas: A New Dimension in Biological Analyses,(Plenum Press, New York; Campbell (1984) Monoclonal Antibody Technology,Laboratory Techniques in Biochemistry and Molecular Biology, ed. Daviset al. 3d ed.; Harper & Row, Philadelphia. Methods for the generation ofpolyclonal antibodies are known, as are techniques of the generation ofmonoclonal antibodies. See, e.g., Kohler and Milstein (1975) Nature256:495-497.

Assay techniques useful in the present invention include, but are notlimited to, assays comprising incubating a biological sample from asubject from a subject suspected of having such a condition in thepresence of a detectably labeled binding molecule (e.g., antibody)capable of identifying the relevant protein, and detecting the bindingmolecule which is bound in a sample. See, e.g., Work et al. (1978)Laboratory Techniques and Biochemistry in Molecular Biology (NorthHolland Publishing Company, NY.

Alternatively, the proteins contained in a particular sample of proteonscan be identified by screening against a panel of phage antibodies inwhich the displayed peptide is a domain of the antibody molecule thatincludes the site that binds antigen. Phage-antibody libraries can beconstructed including billions of clones, displaying billions ofantibodies with different antigen specificities. For a review of thistechnique, see Petrenko and Vodyanoy (2003) J. Micro. Meth. 53:253-262.

The presence of proteons themselves can be detected and quantitated bydark field microscopy. Under high-resolution dark-field microscopyproteons are visualized as bright spherical shapes. Techniques fordark-field microscopy are known in the art. See, e.g., Bradbury andBracegirdle (1998), Introduction to Light Microscopy (MicroscopyHandbooks, No 42), 2d ed.; (Springer Verlag). In particular, proteonsare small, ball-like bodies of different sizes, estimated in the rangeof 50-250 nm. By contrast, healthy erythrocytes appear as bright voidcircles of about 7 microns diameter in the dark-field view, whereasneutrophils are roughly 7-15 microns. When a blood sample comes aged,the morphology and number of the proteons change, with some estimated tobe 500 nm in diameter. Proteons are found in fresh blood of speciesincluding human, bovine, horse, pig, cat, dog, fish, rabbit, and ratblood.

Dark-field microscopy of proteons can be confirmed by transmissionelectron microscopy (TEM) and scanning electron microscopy (SEM)methodology. Techniques for electron microscopy are known in the art.See, e.g., Slayter and Slayter (1992) Light and Electron Microscopy,(Cambridge University Press).

Proteons can be isolated from blood or plasma, i.e., the supernatantproduced by centrifuging a biological material. In one embodiment,proteons can be formed by incubating plasma at 37° C. under sterileconditions over a thirteen day period. At the end of this period, thenumbers of proteons observed under dark-field light microscopy aregreatly increased.

In another embodiment, large numbers of proteons are produced bysubjecting plasma to 120° C. at 20 psi for two hours. The visible numberof proteons is amplified by subjecting plasma to single step of elevatedtemperature.

Efficiency of proteon production is enhanced by taking a small proton ofan amplified sample, adding it to an untreated sample and heating theuntreated sample. These steps can be repeated a number of times, eachiteration yielding an increased quantity of proteons. Accordingly, bydividing the sample into a number of subsamples, subjecting the firstsubsample into the second subsample and carrying out the heating step, agreater concentration of proteons can be produced from the secondsubsample than was produced form the first subsample. These seedingsteps can be repeated multiple times until, after several iterations,the concentration of proteons produced per volume of sample eventuallyplateaus.

Typically, the first two cycles result in a small but significantincrease of proteon population, wherein the third cycle brings about adramatic increase in the number of proteons. Generally, the next threecycles result in saturation of the proteon population.

In one embodiment, a test sample containing a small amount of misfoldedproteins is subjected to a single heating step. The amplified proteonsare quantitated by dark-field microscopy and verified byimmunofluorescent techniques to detect the misfolded protein.

In another embodiment, a small amount of seeds such as the PNCsdescribed above can be added to a test sample to increase thesensitivity of the single step methods. Roughly 5×10¹³ PNC/ml areproduced by initial filtration of plasma through a 5 kD filter. Thisconcentration then can be increased by a factor of roughly 100 byevaporation. Thus, in one aspect, addition of 5 ml of 5×10¹³ PNC/ml to a1 ml sample increases the concentration of PNC in a sample by 2.5×10¹¹PNC/ml. This concentration is increased by a factor of 100 ifpre-concentrated PNC are added. If the initial concentration of PNCvaries from 10⁸ to 10¹¹ PNC/ml, the sensitivity can be increased by afactor of between 250 to 250,000.

In another embodiment, the first step amplification described above iscarried out, then a small portion of amplified sample is introduced intothe untreated sample and subjected to heat again. Then, the smallportion of the second amplified sample is added to the third untreatedsample, heated and so on. The number of cycles depends on the initialconcentration of misfolded proteins. Suitable numbers of cycles include1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, or more.

In one embodiment, the detection and identification can be done as asingle-step method. Apparatus for subjecting a sample to heat and/orpressure are recognized in the art and include without limitation, PCRthermocyclers, autocalves, etc.

As will be recognized by one of skill in the art, both the single- andmultiple-step methods can be manipulated by varying the temperature,pressure, or temporal parameters. Suitable temperatures include 37, 40,45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, or 120°C. Suitable pressures include ambient pressure, as well as 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, or 25 psi. Suitable times of treatmentinclude 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75,80, 85, 90, 95, 100, 105, 110, 115, and 120 minutes.

In another embodiment, these methods can be utilized to clear misfoldedproteins from a biological sample such as blood. Because lowtemperatures can be utilized with long time periods, this can beaccomplished without damaging the biological sample.

In another embodiment, these methods can detect misfolded proteinsinvolved in congophilic disorders. See Kelly (1996) Curr. Op. Struc.Biol., 6:11-17; Kelly (1996) 8:101-106. For instance, there is ademonstrated structural homology between prion and hemoglobin proteins.Korth et al. (1997) Nature 390:74-77. There is evidence that prions arepresent in lymphoid organs and blood. See, e.g., Brown et al. (2001) J.Lab. Clin. Med. 137:5-13; Aguzzi (2000) Lab. Clin. Med. 137:5-13; Aguzzi(2001) Nature Medicine 7:289-290; Wadsworth et al. (2001) Lancet358:171-180. Accordingly, the methods of the present invention can beutilized for amplification of a congophilic protein, thus allowing earlydetection of disorders related to these proteins.

PNC of roughly 1-2 nm and containing about 40-300 atoms play animportant role in capturing hemoglobin released into blood plasma. Whilereleased hemoglobin can be collected by PNCs. Roughly 7×10¹³ PNC arepresent in each milliliter of human blood, while only 0.003% of thewhole pool of PNC is normally linked to proteins and made into proteons.However, a proteon of medium size of 160 nm can collect about 100,000protein molecules of similar size to hemoglobin. Thus, the strongprotein scavenging properties of metal nanoparticles allow them tocollect proteins include misfolded hemoglobin (Kristiansen et al. (2001)Nature 409:198).

Thus, in another embodiment, the present methods can be utilized foramplification of proteins involved in intravascular hemolysis andresulting in aggregation of hemoglobin, including, without limitation,sickle cell anemia, atherosclerosis, malaria, infections and theircomplications, auto-immune disorders, internal bleedings andintravascular hemolysis due to internal prosthetic devices, and toxicreactions. See Kannan et al. (1988) J. Biol. Chem. 263:13766-13773;Schluter and Drenckhahn (1986) PNAS 83:6137-6141 (sickle cell);Fernandez et al. (2001) Antherosclerosis 158, 103-111(atherosclerosis);Papalexis et al. (2001) Mol. Biochem. Parasitology 115:77-86; Esievo etal. (1984) Veterinary Parasitology 15:181-185; Igoe et al. (2002) Clin.Microb. Newsletter 24:69-70; Kreidl et al. (2002) J. Am. Coll. Surgeons194:387; Beckers (2001) Netherlands J. Med:58:204-207 (autoimmunediseases); Ismeno et al. (1999) Int'l J. Cardiology 69:179-183;Klibansky et al. (1966) Toxicon 3:213-216; Seibert et al. (2003) Toxicon41:831-839; Szabo et al. (2002) Thrombosis Research 107:357-363;Kaioumova et al. (2001) Chemosphere 43:801-805.

Using standard techniques, samples for single-step or cyclicamplification can be prepared from homogenates of small tissuefragments, or from biological fluids such as blood, cerebrospinal,lymph, etc. Techniques for the preparation of tissue homogenates andbiological fluids from such sources are known. See Sambrook et al.(1989) Molecular Cloning—A Laboratory Manual, Vols. 1-3 (2d ed; ColdSpring Harbour Laboratory Press, Plainview, N.Y.); and Ausubel et al.,eds. (1994) Current Protocols in Molecular Biology, (Green PublishingAssociates, Inc. and John Wiley & Sons, Inc.).

PNCs can be produced from plasma by filtration through anultrafiltration membrane. In one embodiment, plasma is filteredconsecutively through a 30 kD and a 5 kD CENTRICON™ filter (MilliporeCorp.) before heat treatment. The centrifuge filtration is carried outusing an initial volume of 80 ml centrifuged at 3,500 g for 20 minutes,20° C.

Filtration of plasma before heat treatment abolished proteon formationin the retentate. However, recombination of the recombination of thefractions results in the resumption of proteon formation, and the numberof proteons formed is dependent upon the amount of filtrate added backto the retentate. Thus, the PNCs are present in the filtrate.

Absorption spectra of the filtrate reveals the presence of metals,including copper, zinc, and iron, indicating that PNCs comprise metals.The filtrate was precipitated with 1.2 mM MsSO₄ and TEM studies werecarried out. Such procedures are known in the art. See, e.g., Shindo andOikawa, Analytical Electron Microscopy for Materials Science,Springer-Verlag (2002). It was found that the precipitated extractcontained crystalline metallic nanoparticles of roughly 1-2 nm diameter.Selected area diffraction patterns were consistent with the presence offace centered cubic (FCC) or body centered cubic (BCC) metals orsolid-solution alloys such as FCC copper and BCC iron.

For a review of metal clusters, see Aiken and Finke (1998) J. Mol. Cat.A:Chem. 145:1-44; Gonzalez-Moraga (1993) Cluster Chemistry(Springer-Verlag, New York, N.Y.). High symmetry is one of the maincharacteristics of metal clusters (Gonzalez-Moraga (1993) (Supra). Inaddition, metal clusters bind proteins. See Broun et al. (2002) J. Mol.Biol. 321:341-353; Lui and Xu (2002) J. Inorganic Biochem. 88:77-86.This in one embodiment, the PNCs of the invention are characterized bysmall size, a few nm or smaller. Additionally, the PNCs are present inlarge quantities, about 10¹²-10¹³ PNC/cm³ of blood or tissue, areabundant, present binding sites and strong affinity to proteins, exhibitvariability to bind different proteins, and resist extreme physical andbiochemical conditions.

To test the effects of PNCs isolated from the filtrate upon living cellsvarious amounts of PNCs obtained by ultrafiltration and sterilized byautoclaving were incubated for four hours with various animal cells intissue culture. Significant effects upon cell viability were observed.For instance, rat and mouse glioma cells demonstrated marked signs ofcell death, as assessed both microscopically and by MTT assay.Accordingly, the PNCs of the invention comprise a novel reagent for usein inducing apoptosis, as well as a process for its production. In oneembodiment, aliquots from 1 to 40 μl containing about 1×10¹² to 4×10¹³PNCs were added to 100 μl wells of 96-well ELISA plate. Such compoundsand processes are great for usefulness to those of skill in the art.See, e.g., U.S. Pat. No. 5,344,926 to Murakata et al., titled “Processfor producing staurosporine fermentation process”; and U.S. Pat. No.6,518,032 to Fritz et al., titled “Rapid methods for identifyingmodifiers of cellular apoptosis activity.”

This invention is further illustrated by the following examples thatshould not be construed as limiting.

EXPERIMENTAL Example 1 Production of Proteons from Blood and Analysis byMicroscopy

A 30 μl sample of freshly drawn full blood from a healthy human male wasobtained and diluted in 1000 μl of purified water (17 MOhm) in a 1.5-mlplastic vial, and centrifuged at 2200 g (6000 rpm) to obtain plasma. Anadditional aliquot of the blood was taken and prepared for opticaldark-field microscopy. The plasma was transferred to a 4-ml glass vialwith a plastic cap and a Teflon liner. An aliquot of plasma was againretained for dark-field microscopy. The vial and contents were subjectedto heating at a temperature of 120° C. and 20 psi of pressure for twohours. An aliquot of the heat-treated plasma was prepared for dark-fieldmicroscopy.

Each aliquot retained for microscopy was analyzed by dark-fieldmicroscopy using an OLYMPUS™ microscope fitted with a 100 W mercurylamp, a polarizer, and a Naessens dark-field condenser (COSE Corp.,Canada).

After analysis, the fresh full blood sample was found to containapproximately 3×10⁸ proteons/ml, whereas the diluted sample containedroughly 9×10⁶ proteons/ml. The treated sample contained an estimated3×10¹¹ proteons/ml, a five-order of magnitude increase. Adjusted for theinitial dilution of the blood sample, each milliliter of blood yieldedroughly 1×10¹³ proteons. Thus, within two hours, the number of proteonsincreased by approximately 5 orders of magnitude. Assuming exponentialgrowth, then the number of proteons (N) at any given moment of time (t)can be described by the equation:N=N₀e^(bt)  (1)where N₀ is the initial number of particles, and b is the growthcoefficient. If N, N₀, and t are substituted with the experimentalvalues found in the above experiment, one can estimate that the growthcoefficient (b) for this case is equal to 5.2 1/hour, and the proteonpopulation is doubled every 8 minutes.

As a control, a suspension of phospholipids and cholesterol wassubjected to the same protocol used for the blood sample. However, nostructures resembling proteons were observed under dark-fieldmicroscopy.

Electron microscopy analysis was also carried out on samples obtainedbefore and after heat treatment. Transmission electron microscope (TEM)images obtained from pre- and post-heat-treatment samples reveal smallproteons appearing as dark discs with a rough fibrous appearance. Ananalysis of the TEM images revealed the size distribution of thischaracteristic small proteon to reach a maximum about 150 nm.

Another characteristic form of proteon was observed, a coconut-shapedparticle of about 1-5 microns with a structure resembling one or morenuclei and a cell-like appearance. The nuclei look very similar to thesmall proteons described above. A cross-sectional view of a largerproteon reveals a very distinctive external membrane-like structure.This membrane-like structure, however, looks very different from thebacterial wall or the mammalian cell membrane, appearing as a curlyfibrous shell of 10-12 nm thick. Some fiber-like structures and a fewnuclei are visible inside the proteon. Images obtained by scanningelectron microscopy (SEM) confirm the presence of both small and largecharacteristic proteons.

Example 2 Chemical Composition of Proteons

Energy Dispersive Spectroscopy Analysis

The chemical composition was determined by energy dispersive X-rayspectroscopy using a JEOL JSM-840 SEM system using standard proceduresfor identifying and quantifying elemental composition. Such proceduresare known in the art. See, e.g., Shindo and Oikawa (2002) AnalyticalElectron Microscopy for Materials Science (Springer-Verlag).

A sample of proteons suspended in distilled water was deposited on thealuminum SEM mount and dried in a vacuum for 24 hours. The X-ray spectrawere obtained with an electron beam size of 200 nm at 80 kV for 90 s.Spectra revealed that the proteons were composed of carbon, oxygen,nitrogen, and sulfur, and the presence of potassium, sodium, chloride,silicon, and copper was also detected. The presence of carbon, nitrogen,and sulfur was confirmed by analytical chemical analysis (LecoCorporation, Michigan, U.S.A.). Notably phosphorus, a necessary elementof DNA, was never detected in the proteon samples. On the other hand,all the elements needed for amino acids and proteins are available.

Amino Acid Composition

Free amino acid composition of samples before and after heat and highpressure treatment were determined (LPSA, University of Arizona, Tucson,Ariz.). See Table 3.

TABLE 3 Amino acid composition (pmol/50 μl) No Amino Acid Control*Proteons 1 O-Phosphoserine 98.730 39.878 2 Taurine 191.790 227.739 3O-Phosphoethanolamine 17.980 15.318 4 Urea 220.811 62.573 5 AsparticAcid 137.212 123.086 6 Threonine 365.225 214.981 7 Serine 385.160314.039 8 Asparagine — 95.908 9 Glutamic Acid 483.645 229.149 10Glutamine 287.073 3.920 11 Glycine 985.419 922.430 12 Alanine 443.165448.792 13 Citralline 81.803 — 14 Valine 188.720 236.126 15 Cystine4.799 6.367 16 Methionine — 77.583 17 L-Cystathio-nine 12.301 16.417 18Isoleucine 82.836 76.302 19 Leucine 121.941 139.060 20 Tyrosine 68.63675.682 21 Phenylalanine 104.921 79.904 22 y-Amino-butiric Acid — 108.02223 Etanolamine 36.578 35.605 24 L-Ornithine 53.341 23.004 25 Lysine226.033 208.597 26 Histidine 75.954 103.043 27 Agrinine 273.221 166.512*Preheat and high-pressure treatment plasma.Protein Concentration

The quantitative analysis of proteins in the proteon samples was carriedout by two different protein assays obtained from Bio-Rad Laboratoriesand Sigma Chemical Company according to the manufacturers' protocols.Samples of blood as described in the Example 1 were exposed to differenttemperatures and pressures. Results of the experiments are shown inTable 4.

TABLE 4 Protein concentration in proteon samples BIO-RAD, SIGMA, ProteinProtein concentration, Sample, Condition concentration μg/ml Plasma,control, 25° C. 0.67 ± 0.05 0.85 ± 0.2  Plasma, 56° C., 0.72 ± 0.04 0.98± 0.02 normal pressure, 10 min Plasma, 80° C., 0.68 ± 0.04 1.0 ± 0.2normal pressure, 10 min Proteons, 120° C., 20 psi, 2 hours 0.71 ± 0.041.7 ± 0.2

Gel electrophoresis of plasma and two major protein components ofplasma, albumin and hemoglobin, treated with 120° C. heat and 20 psipressure produce obvious bands of 66,200 D and 14,400 D. Thee are sharedwith albumin and hemoglobin, respectively. After the treatment, thealbumin has two weak bands of 14,400 D. These are shared with albuminand hemoglobin, respectively. After the treatment, the albumin has twoweak bands of 14,400 D and ˜8,000 D, which coincide with the same bandsof proteons. The treated hemoglobin conserved only the 8,000 D band.Proteons filtered through a 100 kD filter conserved the 14,400 and˜8,000 bands, while proteons washed from the filter contain practicallyall bands of plain proteons, indicating that misfolded albumin andhemoglobin may be present in proteons. The confirmation of this fact maybe obtained from the immunoblotting analysis.

Proteons from rabbit blood were disassembled by sodium dodecyl sulfate(SDS), a negatively charged detergent. The fragments of proteins wereelectrophoresed down and made distinctive bands in the polyacrylamidegel. The proteins were identified by N-terminal amino acid sequencing,yielding the partial sequence VLSPA (D/E)(E/K)TN(A/I) (SEQ ID NO:1) thatshows 100% homology with the rabbit alpha chain of hemoglobin. Aminoacid analysis showed that proteons are enriched by hydrophilicnegatively charged amino acids, glutamic and aspartic acids. Proteonsstained with congo-red show an apple-green birefringence with polarizinglight indicating the anisotropic alignment of the dye molecules.

Congo-red staining is indicative of a common structural feature sharedby many amyloids. Specifically, they are stabilized in part byanti-parallel beta sheet extension from one monomer to another. It isbelieved that they dye binds to inter-monomer clefts betweenanti-parallel beta edge strands. See Kelly (1996) Curr. Op. Struc. Biol.6:11-17; Kelly (1996) Curr. Op. Struc. Biol. 8:101-106. One proteinbelonging to the congophilic family is the prion protein associated withthe prion diseases. A structural homology between prion and hemoglobinproteins has been demonstrated (Korth et al. (1997) Nature 390:74-77).In particular, two prion PrP(121-231) molecules could be superimposedwith two β subunits of the crystal lattice of sickle cell hemoglobin1HBS. The superposition included the backbone atoms of residues 145-154,179-189, and 201-217 of the helices 1, 2, and 3 of PrP(121-231) and ofresidue 5-14, 106-116, and 125-141 of the helices 1, 6, and 7 ofhemoglobin S.

Absence of DNA in Proteons

An aliquot of blood pre- and post-treatment (see Example 1) was purifiedusing the DNeasy™ genomic DNA isolation tissue kit (Qiagen) according tothe manufacturer's standard protocols for animal blood and bacteria.After final elution, samples were loaded on 1% agraose gel. DNA bandswere visualized with ethidium bromide. DNA was detected in pre-treatmentsample and undetected in the post-treatment sample.

Similar results were obtained using a HIGH PURE™ PCR templatepreparation kit (Roche Corp.) for isolation of Nucleic Acids followed byfluorometric quantitation of double-stranded DNA using the PICOGREEN®dsDNA quantitation reagent (Molecular Probes Inc.) and a TEACANSPECTRAFLUOR PLUS™ fluorescence and absorbance reader equipped withDELTASOFT™ software for detecting fluorescence (excitation at 485 nm andemission at 535 nm). See Table 4.

TABLE 5 Flourometric quantitation of DNA in blood and proteons. SampleDNA concentration, μg/ml Blood 45.1 Blood after dilution andcentrifugation 3.0 Proteons, freshly prepared 0.033 Proteons, 3 monthsold <0.001

Example 3 Controlled Growth of Proteons

Two identical sets of samples were prepared for this experiment, inwhich the growth of proteons incubated at 37° C. in an atmosphere ofambient air was compared with the growth of proteons incubated in anatmosphere of 5% CO₂. Each set included the following numbered groups:

Group 1. Three ml of freshly prepared proteons (as described in Example1).

Group 2. Three ml of plasma after dilution and centrifugation (asdescribed in Example 1).

Group 3. Ten μl of freshly prepared proteons added to 3 ml of D6429tissue culture media (Sigma Inc.) with 10% FBS (HyClone Labs. Inc.).

Group 4. Ten μl of freshly prepared proteons added to 3 ml of D5648tissue culture media (Sigma Inc.) with 10% FBS (HyClone Labs. Inc.).

Group 5. Ten μl of freshly prepared plasma added to 3 ml of D6429 tissueculture media (Sigma Inc.) with 10% FBS (HyClone Labs. Inc.).

Group 6. Ten μl of freshly prepared plasma added to 3 ml of D5648 tissueculture media (Sigma Inc.) with 10% FBS (HyClone Labs. Inc.).

The experiment was run in duplicate. Uninoculated media were used as acontrol. Samples were analyzed by dark-field and scanning electronmicroscopy at the time points of 0, 2, 4, 8, and 13 days.

Optical observation of proteons was performed with an OLYMPUS™microscope fitted with a 100-W mercury lamp illumination source, apolarizer, a Naessens dark-field condenser (COSE Corp., Canada) and a100× objective (oil, NA 1.4). The dark-field images were directed to aDEI-470T™ microscope video camera (Optronics Engineering, CA) utilizingthe methods described in Vodyanoy et al. (1994) Langmuir 10:1354-1357. Adirect count of proteons was used to determine their concentrations inliquid samples, and IMAGE PRO™ software (Creative Software, Inc.) wasused to quantify the number of proteons.

The number of proteons incubated at 37° C. in an atmosphere of ambientair (Group 1) measured by dark-field microscope did not changesignificantly (p<0.01) during 13 days (FIG. 2A, line 1). The plasma atthe same conditions (Group 2) showed a very small increase in populationof proteons within 8 days of incubation, but the number increaseddramatically and reached the number of proteons in group 1 after 13 daysof incubation (FIG. 2A, line 2). Proteons and plasma in tissue culturemedia (Group 3 and 4, respectively) exhibited the same growth curves andreached the same number of proteons after 13 days of incubation (FIG.2B). The culture media alone incubated at the same conditions showed noproteons (FIG. 2B, bottom line). No significant (p<0.01) effect of CO₂was observed.

Example 4 Reversibility of Construction and Deconstruction of ProteonsIn Vitro

Plasma was prepared as described in Example 1. The samples of plasmawere combined with the guanidine hydrochloride or urea to a finalconcentration of 0, 0.01, 0.1, 1, 4, and 8 M, respectively. Thesechaotropic compounds are known to unfold and denature proteins.

Samples were subjected to heat of 120° C. and pressure of 20 psi. In thesamples to which no chaotropic compounds were added, the numbers ofproteons observed by dark-field microscopy was normally high. The numberof proteons decreased as the concentration of chaotropic compounds wasincreased (FIG. 2C).

Samples of proteons grown at the suppressive presence of 8 M urea weresubjected to dialysis using a Pierce Chem. Co. SLIDE-A-LYSER™ 10Kdialysis cassette (20 h, 5 L, 20° C.) according to the manufacturer'sinstructions. The number of proteons found by dark-field microscopeincreased significantly. Samples of plasma treated with 120° C. heat d20 psi pressure and urea at concentrations of 0.01-8 M were taken.Polyacrylamide gel electrophoresis was carried out on each sample with a4-20% Tris-HCl READY™ precast gel (Bio-Rad Labs. Inc.) according to themanufacturer's protocol. The control (proteons without chaotropiccompounds) showed two characteristic bands of 14,400 and about 8,000 D.The experimental samples (proteons in the presence of a chaotropiccompound) displayed a diffuse distribution of proteins or fragments ofproteins with no sharp bands of proteins of the high molecular massrange. As the concentration of urea increased, the intensity of thediffusion staining decreased, and almost fully disappeared at the 8 Mconcentration of urea. The proton sample displays a 14,400 D band thatcoincides with a similar band found in plasma. When guanidinehydrochloride or urea was added to proteons produced without thechaotropic compounds, heat of 120° C. and pressure of 20 psi resultedalso in a great reduction of number of proteons visible by dark-fieldmicroscopy. Dialysis of these samples restored the population of theproteons. Gel electrophoresis of proteons and plasma treated with 120°C. heat and 20 psi pressure at the presence of urea, and then dialyzed,reveals two bands of 14,400 and about 8,000 D in all samples, includingthose before and after dialysis.

Example 5 Effect of Ultrafiltration on Proteon Formation

PNCs were removed from blood plasma by filtering the plasma through 5 kDCENTRICON™ filters (Millipore Corp.) according to the manufacturer'sprotocol. The protein level in the retentate was quantitated andcompared to that of unfiltered plasma Assay kits were obtained fromBio-Rad Laboratories, and quantitative studies were carried outaccording to the manufacturer's instructions. The amount of protein inthe filtered plasma was the same as that measured in the non-filteredsample. No protein was detected in the filtrate. After filtration,proteons could not be produced until the filtered fraction was returnedto the plasma. The number of proteons was dependent on the amount offiltrate returned to the retentate. Addition of 10 mM of the chelatingagent, ethylene diamine tetra acetate (EDTA), known to form strongcomplexes with metals, also prevented the formation of proteon.Adsorption spectra of the filtrate, determined by energy dispersivex-ray spectroscopy (EDS) and inductively coupled plasma-atomic emissionspectrometry (GTW Analytical Services, TN), revealed the presence ofmetals, including Cu, Zn, and Fe.

Example 6 Analysis of PNCs

To characterize the nature of the PNC nanoparticles, transmissionelectron microscopy (TEM) was utilized. Transmission electron microscopy(TEM) was utilized. Transmission electron microscopy (TEM) was performedusing a JEM 2010™ instrument (JEOL Ltd.), operated at 200 kV.Brightfield (BF) imaging was used to provide an overview of themicrostructure of the sample. Features of interest were characterized byselected area diffraction (SAD) and nanobeam diffraction (NBD, with thelatter set up to produce a narrow (<50 nm diameter), yet near-parallelbeam, so that SAD-like patterns were produced. Dark-field (DF) imagingwas employed to determine which microstructural features gave rise tothe diffraction maxima. The composition of microstructural features wasdetermined (qualitatively) by means of energy dispersive x-rayspectroscopy (EDS). This work employed an ultra-thin window (UTW)detector (Oxford Instruments plc), attached to the JEM 2010™ instrument,together with an ISIS™ analyzer (Oxford Instruments plc).

Scanning electron micrographs were obtained using a JSM-840™ SEM system(JEOL Ltd.). Plasma from rabbit blood was filtered consecutively througha 30 kD and a 5 kD CENTRICON™ filter (Millipore Corp.) before heattreatment. PNCs were precipitated from the filtrate by 1.2 mM MgSO4 atpH 11.3 and transferred onto 400 mesh Ni/carbon grids (ElectronMicroscopy Sciences Co.). Proteon samples for TEM were fixed with 3%gluteraldehyde, dehydrated with ethanol, and embedded in DURCUPAN™ ASMresin (Fluka Co.).

The bulk of the blood precipitate from rabbit plasma was amorphous.However, this extract was found to contain crystalline metallicnanoparticles, with diameters of around 1-2 nm and above. SAD patternsoriginating from different regions of the samples were consistent withthe presence of both face centered cubic (FCC) and body centered cubic(BCC) metals (or possibly solid-solution alloys), with latticeparameters (a₀) of approximately 360 and 290 pm respectively. Thesecombinations of Bravais lattice and a₀ are close to those of FCC copper(a₀=361.50 pm (International Centre Diffraction Data (2001), PowderDiffraction File, ICCD, Newtown Square, Pa.)) and BCC a-iron (“ferrite”,a₀=286.64 pm (International Centre Diffraction Data (2001)), PowderDiffraction File, ICCD, Newtown Square, Pa.)), respectively.Furthermore, both copper and iron were encountered in EDS spectraacquired from the regions containing the nanoparticles. Centered DFimaging demonstrated that the diffraction maxima in these patternsoriginated from the nanoparticles. When viewed in BF, the metallicnanoparticles were very difficult to distinguish from the amorphousbackground in most regions of the samples. Hence, such particles couldeasily have been overlooked in the BF imaging techniques usedconventionally for biological electron microscopy.

The observed crystallography of non-clumped nanoparticles was that ofmetallic iron and copper, rather than of salts of these metals.Furthermore, the diffraction patterns encountered in this work were notproduced by an organometallic structure. The production of evennanometer-sized metallic particles implies assembly of a significantnumber of metal atoms. For example, a 1 nm diameter Cu particle has thesame volume as around 10 Cu, or 20 α-Fe, unit cells. FCC metals have 4atoms per unit cell and BCC metals 2 atoms per cell, indicating aparticle containing around 40 atoms in both cases (similarly, a 3 nmdiameter particle would contain over 1,000 atoms).

Individual metallic nanoparticles had a random crystallographicorientation. Thus, in cases where particles had become clumped (in somecases, this appeared to involve flocculation, in others some of theparticles had sintered together), a polycrystalline aggregate wasproduced. In contrast, within a number of relatively large (around 10 nmdiameter or above) clumps of particles, significant (˜5-10 nm wide)regions were encountered with a constant crystallographic orientation.However, none of the clumps was a true single crystal. Some of theserelatively large clumps contained a number of, as yet unidentified,second phases in addition to α-Fe and Cu.

Both Cu and Fe form stable oxides (for example the Gibbs free energy offormation of even the relatively low stability CuO phase is around −127kJ mol⁻¹ at 300 K). See Brandes and Brook (1992) Smithells MetalsReference Book (7^(th) ed., Butterworth-Heinenmann, Oxford, UK).Furthermore, the initial stages of oxidation of these metals are rapid,even at room temperature. For example, logarithmic oxidation ofinitially bare iron, at an oxygen partial pressure of only 10 mPa,results in the growth of around 2 nm of oxide, after less than 20minutes at 300 K. See Kruger, J. and Yolken (1964), cited by Lawless.(1974) Rep. Prog. Phys. 37(2):231-316. The presence of non-noblemetallic nanoparticles implies that the surrounding organic matrix haseither impeded oxygen access to the metallic particles and/or has asignificant reducing effect.

Many of the nanoparticles survived the coarsening. The surface energy ofthe particles provides a driving force for larger particles tocannibalize smaller particles (the surface area to volume ratio for a1-nm particle is 6×10⁹ m⁻¹ and this drops by an order of magnitude for a10-nm particle). Metallic materials have relatively high solid-vaporinterfacial energies (γ_(SM)<<γ_(SV), there would remain a significantthermodynamic driving force for coarsening. Given the kinetics ofcoarsening, if all that were present were the metallic nanoparticles,room-temperature coarsening, if all that were present were the metallicnanoparticles, room-temperature coarsening would occur at a negligiblerate (solid-state sintering involves bulk diffusion, interfacialdiffusion, free surface diffusion and evaporation and re-condensation,all of which would be very slow for Cu or α-Fe at room temperature). SeeAshby (1974), Acta Metallurgica 29(2):259-281. Although the presence ofthe organic liquid matrix raises possibilities for mass transport, itappears that the matrix did not provide a path for rapid transfer ofmetal atoms since many of the nanoparticles of served in the presentwork remained extremely fine.

Example 7 In Vitro Effect of PNC on Cultured Cells

The impact of PNCs upon viability of various cultured cells wasinvestigated using tetrazollium salt (MTT) cell proliferation assay. RG2(mouse brain glioma), F98 (rat brain glioma), Hs683 (human brainglioma), CTX TNA2 (rat transfected astrocyte), H9c2[2-1](rat heartmyocardium), 27FR (rat skin fibroblast), and SVGp12 (human brainastroglia) cells were obtained from American Type Culture Collection(ATCC) and maintained as recommended by ATCC. MTT cell proliferationassays are commercially available. See, e.g., MTT cell proliferationassay from ATCC.

Cells were plated in Dubecco's modified Eagle's growth medium (D5648,Sigma Chemical, St. Louis, Mo.)+10% fetal bone serum (FBS) (HycloneLaboratories, Logan, Utah) in polystyrene 96-well plates at a density3×10³ cells per well. Twenty-four hours after plating, the medium wasreplaced with DMEM with either staurosporine (100 μl, 1 μM) or PNC(aliquots, 100 μl, 5×10⁹-3×10¹¹ PNC/ml). PNCs were isolated from bloodobtained from shark, dog, and rabbit using the ultrafiltration protocoldescribed in Example 5. PNCs were autoclaved at 120° C. and 20 psi for15 minutes before adding to the cell cultures.

After 20 hours of treatment, a 20-μl aliquot of tetrazolium salt (MTT, 5mg/ml in PBS) was added to the wells, and interaction was allowed toproceed for 4 hours at 37° C. MTT was reduced in metabolically activecells to form purple formazan crystals, which were dissolved by DMSO andquantified by a Bio-Rad™ plate reader. For each cell type, a linearrelationship between cell number and absorbance is established, enablingaccurate straightforward quantification of changes in proliferation.

In two trials, the effect of PNCs on RG2 cells was studied utilizing thefollowing protocol:

-   -   Day 1. Plate out RG2 cells at a density of 3×103 cells/well in        D5648+10% FCS and incubate overnight.    -   Staurosporine (Sigma Inc. Catalog No. S5921), 100 μg, FW 466.5.        Dissolve 100 μg staurospine into 214.3 μl    -   DMSO to equal a 1 mM stock solution. Store at −200° C. Dilute        stock 1:10 in media to equal 0.1 mM or 100 μM stock.    -   Dilute as follows:    -   466.5 gm/1 liter=1 M    -   100 μg/2.143 ml=100 μM (frozen stock)        -   use 10 μl/well=1 μM    -   Day 2. Remove media and add DMEM+1% FCS (100 μl/well). TX put on        late afternoon.        -   Add staurospine, autoclaved shark PNC, and either 10%, 1%,            or 0% FCS treatments to cells and incubate overnight.            The results of this study are shown in Tables 6 and 7,            below. (Ab. Av.=Absorbance at 550 nm; St. Dv.=Standard            Deviation)

TABLE 6 MTT assay on RG2 glioma cells, with 10%, 1% and 0% FCS SharkSeeds - autoclaved 10% FCS 10% 10% 10% 1% 1% 1% 1% no FCS FCS FCS FCSFCS FCS FCS Shark 3 tx 20 μl 10 μl 1 μl no tx 20 μl 10 μl 1 μl 0.5330.298 0.404 0.482 0.731 0.408 0.496 0.707 0.542 0.316 0.414 0.465 0.7530.408 0.496 0.724 0.577 0.374 0.425 0.526 0.74 0.408 0.496 0.605 0.5160.369 0.409 0.467 0.633 0.408 0.496 0.633 0.5 0.321 0.431 0.466 0.6840.408 0.496 0.612 0.362 0.414 0.693 0.408 0.496 0.285 0.373 0.636 0.3840.573 0.298 0.393 0.637 0.431 0.529 Ab. 0.5336 0.32775 0.407875 0.48120.688375 0.405625 0.547875 0.6562 Av. St. 0.029126 0.035568 0.0183490.025994 0.049494 0.023482 0.031197 0.055432 Dv. Stauro- sporine SharkSeeds - autoclaved 10% 10% 1% 0% 0% 0% 0% 0% FCS FCS FCS FCS FCS FCS FCSFCS water water water water Shark 3 no tx 20 μl 1 μl 1 μM 20 μl 20 μl 20μl 20 μl 0.866 0.432 0.739 0.827 0.406 0.436 0.726 0.971 0.891 0.4320.739 0.895 0.411 0.462 0.701 0.74 0.695 0.432 0.739 0.918 0.399 0.3940.676 0.79 0.937 0.432 0.739 0.833 0.799 0.463 .0638 0.78 0.909 0.4790.677 0.928 0.452 0.577 Ab. 0.949 0.551 0.574 Av. 0.87175 0.4666250.648625 0.8506 0.405333 0.430667 0.701 0.833667 St. Dv. 0.0859510.038049 0.059625 0.055599 0.006028 0.034312 0.02 0.121533

TABLE 7 MTT assay, RG2 glioma cells, with 1% FCS, with shark, rabbit anddogs 1 and 2 seeds, autoclaved no 20 μl 10 μl 1 μl 20 μl 10 μl 1 μl txShark Seeds Dog 1 seeds 0.64 0.342 0.447 0.664 0.675 0.773 0.658 0.6940.344 0.616 0.596 0.633 0.705 0.598 0.667 0.373 0.407 0.595 0.527 0.6620.496 0.678 0.322 0.499 0.676 0.57 0.613 0.496 0.675 0.626 0.63 0.630.496 0.634 0.728 0.675 0.496 0.689 0.6 0.703 0.573 0.596 0.719 0.629Ab. 0.6708 0.34525 0.49225 0.6345 0.63525 0.67375 0.644375 Av. St.0.019817 0.020998016 0.090691326 0.038097619 0.07015035 0.052684370.03923168 Dv. stauro 20 μl 10 μl 1 μl 20 μl 10 μl 1 μl 1% Dog 2 seedsRabbit Seeds FCS 0.555 0.595 0.687 0.503 0.62 0.732 0.108 0.568 0.6420.541 0.522 0.577 0.676 0.095 0.543 0.65 0.601 0.476 0.607 0.589 0.0930.529 0.648 0.534 0.512 0.6 0.647 0.561 0.53 0.66 0.585 0.564 0.64 0.5260.638 0.623 0.584 0.604 0.61 0.498 0.593 0.644 0.565 0.519 0.634 0.5660.658 0.559 0.536 0.554 0.649 Ab. 0.54325 0.61925 0.606125 0.5428750.580625 0.647125 0.09866667 Av. St. 0.024294326 0.04372887 0.057137520.0423402 0.03372976 0.0431292 0.00814453 Dv.

Similar studies were carried out comparing the effect of shark PNCs withstaurosporine. See Tables 8-10, below. A significant decrease in cellviability was observed for cultured cells incubated with PNCs for 20hours (FIG. 4A). The viability of the rat and mouse glioma cellsdeclined by 90% and 75%, respectively, while the viability of the ratostrocytes decreased by only 25% at the same conditions. Post-exposuremorphological observations of cells under optical dark-field microscopeshowed signs of cell death. Cells were shrunk and rounded, nuclei werecondensed and showed budding of cell bodies (FIG. 4B-2). Cell damageproduced by the shark PNCs compares well with the injury made by 1 μM ofstraurosporine (a potent apoptosis-inducing reagent) (FIG. 4B-3). Asignificant effect on cell viability was also observed with Hs683 (humanbrain glioma), H9c2[2-1](rat heart myocardium), 27FR (rat skinfibroblast), and SVGp12 (human brain astroglia) cells. Proteons and PNCsobtained from the blood plasma of healthy dog and rabbit alsosignificantly affected the viability of the cultured mammalian cells.

FIG. 4C shows the viability of RG2 glioma cells exposed to PNCs fromdifferent sources. It takes about 1×10¹² PNC/ml to fully suppress theseglioma cells. This concentration accounts for not more than 10% of thefull concentration of PNCs in a healthy animal.

TABLE 8 MTT assay on various cell lines with shark seeds and 0% FCS RG2Fibroblast Myocard No No No tx 1 μl 10 μl 20 μl tx 1 μl 10 μl 20 μl tx 1μl 10 μl 20 μl Plate 1 1.075 0.964 0.856 0.597 0.658 0.503 0.595 0.3420.509 0.452 0.496 0.376 0% 1.169 1.014 0.791 0.496 0.603 0.517 0.5410.36 0.462 0.373 0.471 0.382 FCS 1.103 1.016 0.688 0.523 0.558 0.5560.492 0.375 0.494 0.438 0.462 0.33 1.084 1.082 0.739 0.55 0.556 0.5690.432 0.382 0.449 0.446 0.513 0.309 Ab. 1.10775 1.019 0.7685 0.54150.59375 0.53625 0.515 0.36475 0.4785 0.42725 0.4855 0.34925 Av. St.0.042469 0.048401 0.07191 0.04307 0.048016 0.031298 0.069508 0.0177270.027767 0.036619 0.023302 0.035491 Dv. CTX astrocytes SVG astrocytesF98 glioma No No No tx 1 μl 10 μl 20 μl tx 1 μl 10 μl 20 μl tx 1 μl 10μl 20 μl Plate 1 0.622 0.596 0.555 0.429 0.678 0.688 0.441 0.275 1.0450.914 0.367 0.213 0% 0.603 0.589 0.559 0.489 0.681 05.85 0.439 0.2750.977 0.697 0.444 0.16 FCS 0.59 06.645 0.561 0.396 0.676 0.587 0.4620.251 0.966 0.643 0.415 0.196 0.565 0.6 0.533 0.434 0.656 0.667 0.3630.244 1.064 0.73 0.504 0.172 Ab. 0.595 0.6075 0.552 0.42725 0.672750.63175 0.42625 0.26125 1.013 0.746 0.4325 0.18525 Av. St. 0.023930.02541 0.01291 0.038549 0.011354 0.053525 0.043431 0.016132 0.0487510.117601 0.057274 0.023796 Dv.

TABLE 9 MTT assay on various cell lines with shark seeds and 1% FCS RG2Fibroblast Myocard Plate No No No 2 tx 1 μl 10 μl 20 μl tx 1 μl 10 μl 20μl tx 1 μl 10 μl 20 μl 1% 0.839 0.606 0.536 0.36 0.503 0.44 0.5 0.3070.404 0.43 0.317 0.317 FCS 0.734 0.551 0.723 0.419 0.475 0.452 0.440.316 0.43 0.444 0.349 0.326 0.634 0.595 0.551 0.435 0.465 0.518 0.3510.298 0.408 0.466 0.326 0.289 0.723 0.656 0.564 0.445 0.457 0.547 0.3080.371 0.425 0.458 0.321 0.377 Ab. 0.74025 0.602 0.5935 0.41475 0.4750.48925 0.39975 0.323 0.41675 0.4495 0.32825 0.32725 Av. St. 0.0724590.043135 0.087088 0.038038 0.020067 0.051558 0.086535 0.032833 0.0126850.015864 0.014315 0.036719 Dv. CTX astrocytes SVG astrocytes F98 gliomaNo No No Plate 2 tx 1 μl 10 μl 20 μl tx 1 μl 10 μl 20 μl tx 1 μl 10 μl20 μl 1% 0.521 0.501 0.501 0.355 0.602 0.509 0.352 0.248 0.746 0.6870.376 0.137 FCS 0.507 0.564 0.526 0.415 0.497 0.496 0.37 0.238 0.9710.524 0.334 0.154 0.542 0.562 0.42 0.387 0.534 0.488 0.401 0.246 0.911.267 0.283 0.141 0.538 0.641 0.439 0.471 0.48 0.547 0.394 0.26 0.8640.521 0.309 0.139 Ab. 0.527 0.567 0.4465 0.407 0.55325 0.51 0.379250.248 0.87275 0.74975 0.3255 0.14275 Av. St. 0.016145 0.057347 0.0371890.049207 0.057812 0.026141 0.0225 0.009092 0.095189 0.353447 0.0395850.007676 Dv.

TABLE 10 MTT Assay on various cell lines with Staurosproine RG2 CTXSaurosp 100 nm RG2 Fibro Fibro Myocard myocard astro Shark 7 0.305 0.120.257 0.168 0.402 0.154 0.252 0.301 0.119 0.275 0.166 0.373 0.151 0.518Plate 3 0.279 0.119 0.275 0.171 0.172 0.159 0.533 1% 0.272 0.149 0.2960.171 0.185 0.176 0.21 FCS Ab. Av. 0.28925 0.12675 0.27575 0.169 0.2830.16 0.37825 St. Dv. 0.016215 0.014841 0.015945 0.002449 0.1213620.011165 0.171002 CTX SVG SVG F98 F98 Saurosp astro astro astro gliomaglioma Shark 7 0.212 0.128 0.067 0.136 0.108 0.122 0.12 0.066 Plate 30.118 0.128 0.067 1% 0.126 0.136 0.068 FCS Ab. Av. 0.1445 0.128 0.0670.13325 0.1085 St. Dv. 0.045118 0.006532 0.000816 0.008921 0.000577

Example 8 Cyclic Amplification of Proteons

A progressively increased number of proteons can be produced from plasmasubjected to increasing temperatures. To examine a method of cyclicamplification, seven 1 ml samples of plasma were prepared for cyclicamplification. After the initial number of proteons was quantitated by adark-field microscope, the first sample was incubated for 15 minutes at65° C. and normal pressure. Five μl of the treated first sample wasintroduced to seed the untreated second sample, and the second samplewas incubated for 15 minutes at 65° C. and normal pressure. This stepwas repeated: 5 μl of the second amplified sample was added to the thirduntreated sample. This process was repeated up to 6 cycles. A controlseries was run by adding of five μl of purified water (instead of seeds)to 1 ml of untreated plasma.

The first two cycles resulted in a small but significant (p>0.001)increase of proteon population, whereas the third cycle brought about adramatic increase in the number of proteons. The next three cyclesresulted in saturation of the proteon population. In contrast, thecontrol samples showed no dramatic increase of proteon population. SeeFIG. 2.

Example 9 Comparison with Other Biological Particles

Experiments were carried out to compare the proteons obtained by theprocedure described in the Example 1 with nanobacteria isolated fromblood by Kajander et al. (1996) Mol. Biol. Cell 7:3007-3007 using theNANOCAPTURE™ enzyme linked immunosorbent assay (ELISA) kit for detectionof nanobacterial antigens (Nanobac OY, Finland). The nanobacteriaincluded in the NANOCAPTURE™ ELISA kit were used as a positive control.The BIO-RAD MICROPLATE MANAGER™ 4.01 software (Bio-Rad Labs. Inc.) wasused to obtain the results of the ELISA. The assay procedure was carriedout following the manufacturer's recommendations. The reaction wasconsidered to be positive when the absorbance was significantly higherthen the level of noise. Results of interaction of antibodies grownagainst nanobacteria with proteons and plasma are summarized in Table11.

TABLE 11 Interaction of antibodies specific to nanobacteria withproteons and plasma. No Sample Condition Reaction 1 Proteons, human 1Freshly prepared at 120° C. and 20 psi, 2 h − 2 Proteons, human 2Freshly prepared at 120° C. and 20 psi, 2 h − 3 Proteons, rabbit Freshlyprepared at 120° C. and 20 psi, 2 h − 4 Proteons, human 1 Incubated 13days, 37° C. after preparation − 5 Proteons, human Freshly prepared − 6Plasma, human 1 Incubated 13 days, 37° C. − 7 Proteons, human 1, inIncubated 13 days, 37° C. + D5648^(a) 8 Proteons human 1, in Incubated13 days, 37° C. + D6429^(b) 9 Plasma, human 1 in Incubated 13 days, 37°C. + D5648^(a) 10 Plasma, human 1, in Incubated 13 days, 37° C. +D6429^(b) 11 Proteons, human 1, in Incubated 13 days, 37° C., 5% CO₂-95%air + D5648^(a) 12 Proteons, human 1, in Incubated 13 days, 37° C., 5%CO₂-95% air + D6429^(b) 13 Plasma, human 1, in Incubated 13 days, 37°C., 5% CO₂-95% air + D5648^(a) 14 Plasma, human 1, in Incubated 13 days,37° C., 5% CO₂-95% air + D6429^(b) 15 Proteons, human 1, in Incubated 13days, 37° C., 5% CO₂-95% air + D5648^(a) D5648^(a) Incubated 13 days,37° C. + D6429^(b) Incubated 13 days, 37° C. + 16 D6429^(b) FreshlyPrepared − 17 Water^(c) Freshly Prepared − 18 Broth^(d) 120° C. and 20psi, 2 h − Nanobacteria + ^(a)D5648 tissue culture media (Sigma) with10% FBS (HyClone). ^(b)D6429 tissue culture media (Sigma) with 10% FBS(HyClone). ^(c)Purified water (Direct QTM, Millipore, 17 MOhm)^(d)LB-Medium (BIO 101, Inc.; 10 g Trypton-B, 5 g yeast extract-B, 10 hNaCl in 1 L of water).

Nanobacteria gave a positive signal, while all freshly preparedproteons, showed no interaction. Proteons incubated in cell culturemedia for 13 days, at 37° C. (with and without CO₂) show a positivereaction. However, the culture media alone incubated for 13 days, at 37°C. also gave a positive reaction, while freshly prepared culture mediawas negative, indicating that nanobacterial antigen appeared from theculture media during the incubation.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

All publications and patent applications mentioned in the specificationare indicative of the level of those skilled in the art which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated to be incorporated by reference.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments of the invention described herein, Such equivalents areintended to be encompassed by the following claims.

1. A method for detecting misfolded proteins that bind to proteonnucleation centers (PNCs) and aggregate to form proteons in a biologicalsample comprising: a) contacting the biological sample with isolatedproteon nucleation centers (PNCs), wherein the PNCs comprise metallicnanoparticles that have a diameter of about 1-2 nm and about 40-300metal atoms selected from the group consisting of copper, zinc, iron andalloys of copper, zinc or iron, and wherein the misfolded proteins bindthe PNCs and aggregate to form proteons; and b) detecting the proteonsformed in the sample, thereby detecting the misfolded proteins in thebiological sample, wherein the biological sample is blood or plasma. 2.The method of claim 1, wherein the proteons formed comprise misfoldedprion proteins.
 3. The method of claim 1, wherein the proteons formedare detected with a labeled antibody.
 4. A method for detectingmisfolded proteins that bind to proteon nucleation centers (PNCs) andaggregate to form proteons in a biological sample comprising: a) addingto the biological sample isolated proteon nucleation centers (PNCs),wherein the PNCs comprise metallic nanoparticles having a diameter ofabout 1-2 nm and about 40-300 metal atoms selected from the groupconsisting of copper, zinc, iron and alloys of copper, zinc or iron, andwherein the misfolded proteins bind the PNCs and aggregate to formproteons; b) heating the biological sample to amplify the concentrationof proteons; and c) detecting the proteons formed in the biologicalsample, thereby detecting the misfolded proteins in the biologicalsample, wherein the biological sample is blood or plasma.
 5. The methodof claim 4, wherein the sample is heated for at least about 1, 5, 10,15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100,105, 110, 115, or 120 minutes.
 6. The method of claim 4, wherein thesample is heated to a temperature of at least 37, 40, 45, 50, 55, 60,65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, or 120° C.
 7. The methodof claim 4, further comprising applying pressure to the sample of atleast 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 psi.
 8. Themethod of claim 4, wherein the proteons formed comprise misfolded prionproteins.
 9. The method of claim 4, wherein the proteons formed aredetected with a labeled antibody.
 10. A method for detecting misfoldedproteins that bind to proteon nucleation centers (PNCs) and aggregate toform proteons in a biological sample, wherein the biological sample isblood or plasma, the method comprising: a) adding to the biologicalsample isolated proteon nucleation centers (PNCs), wherein the PNCscomprise metallic nanoparticles having a diameter of about 1-2 nm andabout 40-300 metal atoms selected from the group consisting of copper,zinc, iron and alloys of copper, zinc or iron, and wherein the misfoldedproteins bind the PNCs and aggregate to form proteons; b) heating thebiological sample for amplification of the proteons; c) repeating stepsa) and b); and d) detecting the proteons formed in the biologicalsample, thereby detecting the misfolded proteins in the biologicalsample.
 11. The method of claim 10, wherein steps (a) and (b) arerepeated until the number of proteons formed in the sample no longerincreases.
 12. The method of claim 10, wherein the sample is heated forat least about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70,75, 80, 85, 90, 95, 100, 105, 110, 115, or 120 minutes.
 13. The methodof claim 10, wherein the sample is heated to a temperature of at least37, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115,or 120° C.
 14. The method of claim 10, further comprising applyingpressure to the sample of at least 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24 or 25 psi.
 15. The method of claim 10, wherein the sample isheated for at least 15 minutes at a temperature of at least 60° C. andsteps a) and b) are repeated at least six times.
 16. The method of claim10, wherein the proteons formed comprise misfolded prion proteins. 17.The method of claim 10, wherein the proteons formed are detected with alabeled antibody.